A vacuum motor shouldn't turn right?!

[Mich88XJ]

Hi, I thought I had my 4wd problem narrowed down to the solenoid on the Tcase, but after replacing it, 4wd still doesn't work. At first it engaged fine, but then when it went to disengage, it wouldn't, so I had to pull a vacuum line to the shift motor. Anyhow, then it wouldn't shift back into 4wd, but when I was wheeling in some dunes, it did, but wouldn't disengage again. That is when I noticed that I could turn the vacuum motor by hand. Anyhow, I don't think this is right, but does the problem sound like the motor, or what? I havent replaced the lines, but the whole turning thing I thought signaled a problem. Thanks for your help, I wanna be back wheeling soon!

[Eagle]

Could you explain what you mean by "turn" by hand? I haven't actually looked at the shift motor on my '88 since I replaced the vacuum harness two or three winters ago, but I don't recall there being anything that could be turned, by hand, by wrench, or by any other external means. The shift motor doesn't "turn" anything, anyway -- it slides a collar, similar to a synchro in a manual transmission.

[sternbal]

Yes, it is ok for the motor portion to rotate along its axis in the housing.

Have you checked the vacuum lines to make sure they have vacuum when they're supposed to?

Have you checked the operation of the motor by applying a vacuum with a hand pump and making sure that it will move the motor and will hold vacuum for a reasonable time?

I don't remember off hand which port does what, but one is to engage the axle, one is to disengage it, and the other sends vacuum to the 4wd light switch when it is engaged.

[Mich88XJ]

Okay, I will give that a try, thanks. Any other ideas would be helpful!